It is reasonable to believe that certain angels, as well as certain demons, have been given specialized tasks and possibly even areas assigned to them. The Prophet Daniel, in chapter 10, may be speaking of a situation where spiritual powers battle over certain geographical areas (Daniel 10:13,14,20). Also, Isaiah 34:14 speaks of God leaving Edom desolate and as a place of habitation only for various animals, but also demons (“night creatures” or even “demons” most probably being a better rendering). So it is possible that certain geographical areas might be associated with demons, and possibly certain individual demons. It is even possible that some of the names of local Gods and Goddesses derive from the personalities of these local demons.
However, I do not think there is sufficient Biblical data to form a biblical doctrine of territorial spirits.
Such things are speculation at best. The Daniel reference to “The Prince” in Daniel 10, presumably a spirit being, could also be referring to a human personage such as Cambyses, one of Cyrus’ princes, who was actively prohibiting the building of the temple, the topic for which Daniel was praying. Also, it is hard to swallow that an angel sent from heaven could be blocked for 21 days by a territorial spirit. Why would an angel even need go from heaven through Babylon to get to Jerusalam, as if the path from heaven to Jerusalem necessarily went through Persia? Unclear texts make wobbly doctrinal supports.
Despite the lack of clear biblical evidences for territorial spirits, some spiritual warfare advocates have attempted to “map” the territories of different spiritual beings. Some have set out on “prayer walks” to bind the regional demons through prayer so that the Gospel, at least, can penetrate these unreached areas.
This is folly. Save the money and pray from home, your soles need not circumnavigate an area for your prayers to be received in heaven.
Finally, we need to ask this question: is God any less powerful in one geographical location than another? Is His control any less in one place as compared to another placed based on the strength of the local deities worshipped by the lost in a particular locale? Not at all. For instance, though, the K__ Tribe where I work may fear the demons Saip and Walupul, and there may, indeed, be spiritual realities behind these fears, my methodology does not change in the least. The Gospel is what is needed.